(1) Field of the Invention
The present invention relates to a photo-detecting device, and more particularly to a photo-detecting device in a solid-state image sensor.
(2) Description of the Related Art
Charge-coupled device (CCD) or metal-oxide-semiconductor (MOS) solid-state image sensors are mounted on digital still cameras, camcorders, and the like. Such solid-state image sensors convert light incident on photo-detecting devices into electric charges. In the CCD solid-state image sensor, the generated signal charges are accumulated in potential wells, and then transferred. In the MOS solid-state image sensor, on the other hand, the generated signal charges are read out as voltage directly from the photo-detecting devices using MOS transistors. Imaging areas in those solid-state image sensors, in which the photo-detecting devices are two-dimensionally arranged, have red-green-blue (RGB) primary color filters with the Bayer or stripe type color array for colorization (for example, refer to Japanese Patent Laid-Open No. 5-183139 publication).
FIG. 1 is a cross-sectional view showing structures of the photo-detecting device in the conventional MOS solid-state image sensor and its periphery.
The conventional solid-state image sensor is comprised of: a plurality of photo-detecting devices 810 that is a plurality of n-type regions formed in a p-type silicon substrate 800; a color filter 820 that is placed at light incident side of the photo-detecting devices 810; and a plurality of output amplifiers 830 that have each MOS transistor 831, that are connected with the photo-detecting devices 810, and that convert signal charges into voltage, and amplify and output the voltage.
It should be noted that RGB primary colors in the color filter 820 are arranged in the Bayer type color array as shown in FIG. 2.